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Item Novel zinc(ii) derivatives of phenol schiff bases: synthesis, characterisation, crystal structure and antimicrobial activity(The Journal of Engineering and Exact Sciences, 2018) Santos, A. F. da S.; Souza, M. C. de; Diniz, R.; Maia, J. R. da S.Zinc(II)-Schiff base derivatives of general formula [Zn(L)Cl] n.xH2O {n = 2; x = 1, L = 3- hmp (1), L = 4-hmp (2); x = 0, L = hmyp (3)} were synthesized by the condensation reaction of aminophenol with 2-hydroxybenzaldehyde. The Schiff bases in complex-1, 2 and 3 are bonded to the metal through the nitrogen and oxygen atoms. These complexes have dimeric structures with bridging oxygen atom. The metal is at the centre of a tetrahedron (1 and 2), and at a square pyramidal geometry (3), according to the X-ray diffraction analyses. They were characterized by IR, NMR (1H, 13C), molar conductivity, melting point and microanalyses. The bioassay of these Zn(II) derivatives on strains of S. aureus, B. subtillis, E. coli and S. typhimurium showed MICs between 60 and 520 μM. Complex-2 showed the best antibacterial result with MIC of 65 μM against the Gram-positive bacteria.Item A pentacyclic triterpene from Maytenus imbricata: structure elucidation by X-ray crystallography(Structural Chemistry, 2006-02) Pimenta Jr., Alécio Antonio; Silva, Sílvia Ribeiro de Souza e; Silva, Grácia Divina de Fátima; Barbosa, Luiz Cláudio de Almeida; Ellena, Javier; Doriguetto, Antonio CarlosA pentacyclic triterpene, 3β,30-dihydroxy-lup-20(29)-ene, was isolated from the powder extract of Maytenus imbricata. The structure and stereochemistry of the compound were established by spectroscopic techniques and unambiguously determined by single crystal X-ray crystallography. The crystal structure shows one molecule in the asymmetric unit. The crystal packing is stabilized by O–H···O intermolecular hydrogen bonds, which give rise to infinite helical chains along the c unit cell axis. The intra-molecular geometry was analyzed using MOGUL, a knowledge base of molecular geometry derived from the Cambridge Structural Database (CSD).Item Influence of hydrogen bonds on the molecular structure and conformations of two (C30H48O2) pentacyclic triterpene isomers(Journal of Structural Chemistry, 2012-02) Barbosa, L. C. A.; Corrêa, R. S.; Silva, S. R. Souza e; Duarte, L. P.; Silva, G. D. F.; Ellena, J.; Doriguetto, A. C.The structural study of two (C30H48O2) pentacyclic triterpene (PCTT) isomers is presented. These terpenes, known as 30-hydroxy-lup-20(29)-en-3-one (1) and (11α)-11-hydroxy-lup-20(29)-en-3-one (2), were isolated from Maytenus imbricata Mart. Ex Reissek (Celastraceae). The molecular structure of 1 and 2 differs in the position of the hydroxyl group. Both compounds crystallize in non-centrosymmetric space groups with two molecules in the asymmetric unit. The crystal structure of 1 shows a triclinic P1 space group (a = 9.5518(1) Å, b = 9.7083(1) Å, c = 14.4696(2) Å, α = 93.832(1)°, β = 102.833(1)°, and γ = 103.307(1)°), while compound 2 crystallizes in a monoclinic P21 one (a = 13.4439(16) Å, b = 14.4463(14) Å, c = 13.5224(9) Å and β = 99.703(8)°). The two molecules independent by symmetry of 1 differ slightly due to the presence of static disorder in oxygen atoms. In addition, the intermolecular geometries of 1 and 2 were analysed, and in each isomer the crystal packing is stabilized by O-H…O intermolecular hydrogen bonds and van der Waals forces.Item Synthesis, structural and spectroscopic characterization of novel zinc(II) complexes with N-methylsulfonyldithiocarbimato and N-methylsulfonyltrithiocarbimato ligands(Polyhedron, 2007-01-02) Oliveira, Marcelo R. L.; Perpetuo, Genivaldo J.; Janczak, Jan; Rubinger, Mayura M. M.Two new zinc(II)-complexes, dithiocarbimato (Ph4P)2[Zn(CH3SO2N=CS2)2] (1) and trithiocarbimato (Ph4P)2[Zn(CH3SO2N=CS3)2] (2), were obtained in the crystalline form by the reaction of potassium N-methylsulfonyldithiocarbimate (RSO2N=CS2K2) with zinc(II) acetate dihydrate and tetraphenylphosphonium chloride in dimethylformamide. Both complexes crystallize in the monoclinic system. The central Zn(II) ion has a distorted tetrahedral coordination in both compounds. In 1 the dithiocarbimato ligand coordinates via two S atoms while in 2 the trithiocarbimato ligand coordinates via S and N atoms. Both complexes were also characterized by IR, 1 H NMR and 13C NMR spectroscopies. Compound 2 is the first example of a zinc(II)-trithiocarbimato complex.Item Preparation, crystal structure and spectroscopic characterization of nickel(II) complexes with dithiocarbimate derivated of sulfonamides(Polyhedron, 2006-07-10) Oliveira, Marcelo R. L.; Franca, Eduardo de Faria; Guilardi, Silvana; Andrade, Renato Pereira de; Lindemann, Renata Hernandez; Amim Jr., Jorge; Ellena, Javier; Bellis, Vito M. de; Rubinger, Mayura M. M.This work describes the syntheses of three compounds containing [Ni(RSO2N=CS2)2]^2 anions: (Bu4N)2[Ni(CH3CH2SO2N=CS2)2] (1), (Bu4N)2[Ni(4-IC6H4SO2N=CS2)2] (2) and (Bu4N)2[Ni(2,5-Cl2C6H3SO2N=CS2)2] (3). They were obtained in the crystalline form by the reaction of the appropriate potassium N-R-sulfonyldithiocarbimate (RSO2N=CS2K2) with nickel(II) chloride hexahydrate in methanol/water. Elemental analyses were consistent with the proposed formulae. UV–Vis and IR data are consistent with the formation of nickel–sulfur diamagnetic planar complexes. The 1H NMR and 13C NMR spectra showed the expected signals for the tetrabutylammonium cation and the dithiocarbimate moieties. Single crystal structure analyses showed that 1 crystallizes in the monoclinic space group P21/n, 2 crystallizes in the monoclinic space group P21/c and 3 crystallizes in the triclinic space group Pī. In these compounds the Ni. atom is coordinated to four S atoms in a distorted square plane geometry due to the asymmetric bidentade chelation by each ligand.Item Conformerism, enantiomorphism and double catemer motifs in para-substituted nostoclide analogues(Journal of Molecular Structure, 2016-02-15) Teixeira, Róbson Ricardo; Barbosa, Luiz Claudio Almeida; Antolinez, Isabel Valero; Corrêa, Rodrigo de Souza; Martins, Felipe Terra; Doriguetto, Antônio CarlosWe have here elucidated the crystal structures of five nostoclide analogues. A common feature in all compounds is a substituent at the para-position of the benzylidene group. Compounds with either bromine (3) or hydroxyl (4) as para-substituent crystallizes with Z’ = 2 as result of conformerism. It was also observed that Z' > 1 in the compound with a para-dimethylamino substituent (1). However, its four crystallographically independent molecules are conformationally similar. They are not related by crystallographic symmetry due to the offset packing of their C–H … OC nonclassical hydrogen bonded double chains. This compound (1) has also crystallized in a chiral space group (P21) despite the lack of a stereocenter. Such enantiomorphism phenomenon is related to the presence of only one of the two mirror benzyl conformations with phenyl ring at the equatorial position opposite the lactone oxygen atom. The molecular mean plane of nostoclide analogues has been featured by high level of planarity, except in the brominated compound where two twisted conformations occurred due to rotations on the single bond axis into benzylidene group. The benzyl conformation has been the greatest difference between the two crystallographically independent molecules of the para-hydroxylated compound (4). The crystal packing of the compounds is marked by double catemer motif assembled through C–H … OC non-classical hydrogen bonds, although C–H … π interactions do play an important role in stabilizing the crystal packing of some compounds of the series.Item Syntheses, structural and spectroscopic characterization of novel zinc(II)-bis(trithiocarbimato) complexes and bis(N-methylsulfonyldithiocarbimate) -sulfide(Polyhedron, 2012-01-04) Tavares, Eder do Couto; Oliveira, Marcelo Ribeiro Leite; Janczak, Jan; Vieira, Camila Grossi; Alves, Leandro de Carvalho; Castro, Rodrigo Antunes; Vieira, Lígia Maria Mendonça; Lindemann, Renata Hernandez; Perpétuo, Genivaldo Júlio; Visconte, Leila Léa Yuan; Rubinger, Mayura Marques MagalhãesFour zinc(II)-bis(trithiocarbimato) complexes with the general formula A2[Zn(RSO2NCS3)2] [A = Ph4P+: R = CH3 (1), 4-CH3C6H4 (2); A = Bu4N+: R = CH3 (3), 4-CH3C6H4 (4)] were obtained by the reaction of sulfur with the correspondent zinc(II)-bis(dithiocarbimato) complexes. Additionally, the compound (Ph4P)2[(CH3SO2NCS2)2S)] (5) was prepared from the potassium methylsulfonildithiocarbimate by oxidation with iodine. The compounds were characterized by elemental analyses and IR, 1H NMR and 13C NMR spectroscopies. The compounds 4 and 5 were also characterized by X-ray diffraction techniques. The compound 4 crystallizes in the centrosymmetric space group C2/c of the monoclinic system. The Zn(II) is in a distorted tetrahedral environment (ZnS4) in compound 4, and differ from the coordination mode observed in compound 1, which involves one sulfur and one nitrogen atom of each trithiocarbimate ligand. Compound 5 is the first example of a compound containing a bis(N-alkylsulfonyldithiocarbimate)-sulfide dianion and crystallises in the non-centrosymmetric space group P41212 of the tetragonal system.Item Syntheses, characterization and antifungal activity of heteroleptic nickel(II) complexes with N-alkylsulfonyldithiocarbimates and phosphines(Journal of Molecular Structure, 2016-06-15) Vidigal, Antonio E. C.; Rubinger, Mayura M. M.; Oliveira, Marcelo R. L.; Guilardi, Silvana; Souza, Rafael A. C.; Ellena, Javier; Zambolim, LaercioFour nickel(II) complexes of general formula [Ni(RSO2NCS2) (PPh3)2] where R = CH3 (2a), CH3CH2 (2b), CH3(CH2)3 (2c) and CH3(CH2)7 (2d) and PPh3 = triphenylphosphine; and two nickel(II) complexes of general formula [Ni(RSO2NCS2)dppe] where R = CH3(CH2)3 (3c) and CH3(CH2)7 (3d) and dppe = 1,2-bis(diphenylphosphine)ethane) were prepared. These new complexes were obtained by the reaction of nickel(II) chloride hexahydrate with potassium N-alkylsulfonyldithiocarbimates and the appropriate phosphine using ethanol/water as solvent. The IR, UV–Vis and ^1 H, ^13 C and ^31 P NMR spectra, elemental analysis of Ni and the HR-ESI-MS were consistent with the formation of square planar nickel(II) complexes with mixed ligands. The structures of the compounds 2b and 2c were determined by single crystal X-ray diffraction. The compounds are isostructural and crystallize in the space group P of the triclinic system. The activities of the complexes were investigated in vitro against Botrytis cinerea, Colletotrichum acutatum and Alternaria solani, fungi species that affect various commercially important plants. All the complexes were active.Item Structural variety of 2-amidoethyltin compounds(Journal of Organometallic Chemistry, 2017-10-15) Menezes, Daniele C.; Lima, Geraldo M. de; Wardell, James L.; Gomez-Banderas, Jessica; Harrison, William T.A.The syntheses, spectroscopic data and crystal structures of (H2NCOCH2CH2-C)(R2NCS2-S,S′)3Sn (1), (H2NCOCH2CH2-C,O)2SnCl2 (triclinic polymorph) (2), (H2NCOCH2CH2-C,O)(2-H2NCOC6H4S-O,S)SnCl2 (3) and Sn(C11H9N2O2)Cl3 (4) are reported. The tin atom in compound 1 (R = Et) is coordinated by three chelating dithiocarbamate anions and a C-bound non-chelating amidoethyl ligand to generate a SnS6C pentagonal-bipyramidal coordination polyhedron. Compound 2, which features SnC2O2Cl2 octahedra, was crystallised from mixed solvents (ethanol and water) and complements the two known monoclinic forms. Compound 3 arose unexpectedly due to ligand disproportionation of the tin starting material and a “trans-esterification” reaction of the starting ligand: distorted SnCSO2Cl2 octahedra are seen in the crystal structure. Compound 4 arose from another ligand disproportionation reaction and features neutral complex molecules with N2OCl3 donor sets coordinating to the octahedral tin atoms.